More information about the new issue can be found in Storylines & Release Dates Here, and goes as follows:

Back To The Future #22

“TIME SERVED, PART 1!” On a mission to uncover the secrets that sent Jailbird Joey Baines to prison, Marty is trapped in 1972—and the DeLorean has vanished! Things go from bad to worse when Biff Tannen teams with 18-year-old Joey to break into a house… and they drag Marty along! Their target: Doc Brown’s mom!!!